Thread: Question regarding Composite fxns with fractions

These are the two fxns

f(x) = (x+1)/(x-1)

g(x) = 1/x

I have to find f o g and f o f.

I tried to work it out but in f o g, it's too confusing what to do with the fraction in a fraction and in f o f it's in the num and denom.

I know the answers but not how to solve...

f o g = (1 + x)/ (1 - x)

f o f = X

Please help to find how to solve this! Thanks.

Originally Posted by D-Rose

These are the two fxns

f(x) = (x+1)/(x-1)

g(x) = 1/x

I have to find f o g and f o f.

I tried to work it out but in f o g, it's too confusing what to do with the fraction in a fraction and in f o f it's in the num and denom.

I know the answers but not how to solve...

f o g = (1 + x)/ (1 - x)

f o f = X

Please help to find how to solve this! Thanks.

Try

I don't understand how you went from Step 2 to 3...did something with the reciprocal of one of the fractions?

Originally Posted by D-Rose

I don't understand how you went from Step 2 to 3...did something with the reciprocal of one of the fractions?

Hi, you probably need some practice combining fractions.
Is the following ok?

Wow haha, I knew that but didn't think. Thanks!